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Bayesian Variable Selection In Quantile Regression

Posted on:2013-11-22Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y G JiFull Text:PDF
GTID:1220330395471086Subject:Probability theory and mathematical statistics
Abstract/Summary:
Since the seminal work of Koenker&Bassett[1](1978), quantile regression isgradually emerging as a comprehensive approach to the statistical analysis of linearand nonlinear response models. Compared with the mean regression, quantile re-gression can provide a more complete picture for the distribution. In practice, if thepredictor vector contains many variables, then it is necessary to select the signif-cant ones in order to improve the precision of the estimator. In this paper, based onthe stochastic search variable selection approach, we develop a simple and efcientGibbs sampling algorithm for Bayesian model selection in quantile regression basedon a location-scale mixture representation of the asymmetric laplace distribution.Also, we extended the approach in binary and tobit quantile regression. More-over, we consider variable selection in the single-index quantile regression modelbased on the stochastic search variable selection approach, where the link functionis modeled by trucated linear splines, and the distribution of the error is mod-eled nonparametrically by a Dirichlet process mixture model. Posterior inferenceis implemented using the Gibbs sampling and Metropolis-Hastings algorithm. Theabove models are illustrated using a large number of simulations. The results showthat our methods can efectively choose the true model. At last we analysis severalreal data examples.
Keywords/Search Tags:Bayesian model selection, Quantile regression, Gibbs sampling, Scale uniform mixtures distribution, Dirichlet process mixture model, AsymmetricLaplace distribution, Binary quantile regression, Tobit quantile regression, Singleindex quantile model
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